Automatic belt positioner



March 1950 w. L. SULLIVAN El AL 2,499,934

AUTOMATIC BELT POSITIONER '2 Sheets-Sheet 1 Filed March 11, 1947 Patented Mar. 7, 1950 AUTOMATIC BELT POSITIONER Warren L. Sullivan and Frederick G. Wilde, Rochester, N. Y.,' assignors to Paragon Revolute Corporation, Rochester, N. Y., a corporation of New York Application March 11, 1947, Serial No. 733,806

1 Claim.

This invention relates to photographic developing apparatus and to an automatic belt positioner adaptedfor use therewith.

In the copending application of Sullivan'et 2.1., Serial No. 607,830, filed July 30, 1945, now Patent No. 2,475,809, dated July 12, 1949, there is disclosed a machine for developing photosensitized sheets by means of ammonia gas or the like. In that machine, a driven, impervious belt guides the photosensitized sheets past an opening in a chamber containing the developing gas, the belt also serving to seal the gas within the chamber. Since the-belt must seal the opening in the chamber, it should not deviate from its intended path of travel, otherwise it Will permit the developing gas to escape.

In accordance with the present'invention, there is provided means for automatically restoring such a guide belt to its intended course of travel, in the event that it tends to creep to one side or the other of that course.

The various features and advantages of the invention will appear from the detailed description and claim when taken with the drawings in which:

Fig. 1 is a vertical section through a developing machine of the type referred to, in which the'automatic belt positioner of the present invention is incorporated;

Fig. 2 is a view of the automatic belt control means of the present invention looking at right angles to the course of travel of the belt; and

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.

In the drawings, the numeral 5 designates a generally rectangular cabinet which houses the developing apparatus. Within the cabinet, there is provided a developing chamber (Fig. 1) in which there is contained ammonia gas or other developing gas for processing a photosensitive sheet (not shown). This developing chamber comprises a sheet metal structure 6 which is substantially trough-shaped in crosssection (Fig. 1) with its right-hand edge 1 attached to a cylindrical guide 8. The opposing side 9 of the trough, extends vertically and its margin i0 is attached to a second cylindrical guide I l similar in construction to the first. The chamber, with its marginal cylindrical guides, is preferably coextensive with the width of the machine, the edges of the chamber being sealed to the end plates [2 and I3 respectively.

By this construction, the portion of the chamber C adjacent the front of the machine is closed toward the rear of the machine is open. The open portion of this chamber is closed by means of a belt M which passes around the driven roller l5 at the lower part and the idler roll I6 at the upper part of the machine. The idler roll it is supported in bearings which are adjustable by means of the screws I! to tighten or loosen the belt, as desired. This belt, which is preferably made of rubber or other flexible material, is impervious to ammonia or other developing gas. As it travels, the belt wipes over the cylindrical guides 8 and H, and its edges engage parts (not shown) on the end frames, such as I2 and 13 to provide an effective seal for the open side of the developing chamber. This arrangement substantially eliminates the leakage of gas from the developing chamber. Within the chamber, there is provided a heated evaporating tray into which a uniform supply of aqua ammonia or the like is introduced, the tray functioning to evaporate the aqua ammonia and thereby fill the chamber with ammonia gas.

The photosensitive sheet to be processed, is supported against the under surface of the belt [4 by series of rollers it freely rotatable on bearings (not shown) in the end frames. These rollers, which may be solid or porous, as desired, arespaced apart to allow the processing gas to have access to the photosensitive sheet at the several areas between the rollers as well as through the rollers themselves. In order to insure that the photosensitive sheet will follow its intended path along the under surface of the belt [4 and not be diverted between the rollers l8 into the chamber, there are provided a series of parallel guide rods 59, of which only one is shown. The guide rods have their respective ends mounted, as indicated, at points 20 and M in the cylindrical guides 8 and H (Fig. 1) and completely rest in channels in the several rollers l8. Preferably the exposed surfaces of the guide rods l9 at the channels, are substantially flush with the surfaces of the rollers l8.

The photosensitive sheet is introduced at A between the belt I4 and the cylindrical guide 8 at the lower part of the cabinet, being directed to this point by the guide plate 24. The photo- Whereas the portion of the chamber directed sensitive sheet is moved upward by the belt l4 over the rollers 3, being exposed at this time to the processing gas which enters through the spaces between these rollers. The processed sheet emerges from between the belt l4 and the upper cylindrical guide II at point 25 to drop into a receptacle R.

In accordance with the present invention,

means are provided for automatically restoring the belt I4 to its intended course in the event that it tends to creep toward one side. This means includes an automatic control roller 33 with which the belt engages. This roller, located at the rear of the apparatus, is supported at its left end (Figs. 2 and 3) in bearing 34 carried by the bearing holder 35. This holder is mounted for pivotal movement about the pivot 36 which is adjustably supported in the bracket 31 for movement toward and away from the belt 14. The roller is supported at its right end in a bearing 38 held in the bearing holder 39. This bearing is retained against outward movement from the belt by a guide 4! which is supported on the end plate 13. The bearing 38 is suspended by a coil spring 45 supported at 44. Thus the control roller 33 is pivotally supported at its left end and is suspended by a spring 45 at its right end so that it can move in the plane of the adjacent surface of the belt, to various positions in inclined relation to the edges of the belt. In these several positions the control roller will be held against the belt. In the present arrangement, an automatically movable pushrod 46 engages the upper surface of the bearing holder 39 to act against the spring 45. Preferably, the pushrod 4B is made in two parts, one of which screws into the other as indicated at 46a so that the length of the rod can be changed at will. The upper end of the rod is attached to the left end (Fig. 2) of the arm 48 of a bell crank lever which is also provided with a downwardly extending arm 49. This lever is pivotally supported at on a bracket 52 which in turn is supported on the end plate l3. The lower end of the bell crank lever 49 has fixed thereto an angular support 54. This support carries a shoe 55 against which the edge of the belt rubs. From the shoe, there project three fingers 56, 51 and 58, the fingers 5B and 58 engaging one surface of the belt and the finger 57 engaging the other surface thereof. Thus, these fingers maintain the shoe in alinement with the edge of the belt.

When the belt is installed, the screw I! (Fig. 1) at the left end of the machine, as viewed in Fig. 2, is adjusted to move the left end of idler roller IS in a direction to tighten the left side of the belt. It will be noted that the pivoted end of the automatic control roller 33 is likewise at the left side of the machine (Fig. 2). The

4 mentioned adjustment of the idler roller to tighten the left side of the belt, tends to cause the belt to move away from the tight side, namely, toward the shoe 55. The resulting movement of the shoe 55 causes the bell crank lever to force the pushrod 46 and the bearing holder 39 which it contacts, in a downward direction. The bearing holder 39 lowers the right end of the control roller 33 tending to tighten the right side of the belt. The tightening of the right side of the belt will tend to move the belt toward the left. After a short time these two forces will balance each other so that the belt will stay in its finally adjusted position. In other words the tightness of the belt M at one side thereof as effected by the adjusting screw l1, together with the sloped position of the automatic control roller 33, will resist any tendency of the belt to creep toward one side or the other.

What we claim is:

In an arrangement of the class described a driven roller, an idler roller parallel thereto, a belt passing around said idler roller and said driven roller to be driven by the latter, a control roller engaging one surface of said belt and pivoted adjacent one edge of said belt for movement in the plane of said surface of said belt, means including a spring for supporting the other end of said control roller, a pushrod movable to force the last mentioned end of said roller downward against the action of said spring, and a bell crank lever mounted on a fixed support, one arm of said lever serving to move said pushrod, and means carried by the other arm of said lever for engagement with the edge of said belt to be moved thereby.

WARREN L. SULLIVAN. FREDERICK G. WILDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 14,621 Wait Apr. 8, 1856 922,568 Loutensock May 16, 1911 1,757,950 Allin May 13, 1930 1,841,482 Langsner Jan. 19, 1932 1,842,946 Prins Jan. 26, 1932 

